3 basics for you who handle colors and lab dips


1. Metamerism is a big issue in the textile and dyeing industry

The metamerism phenomenon is visible when TWO samples/garments appear to have the same color under one light source (such as in store), but show a different shade under another light source (such as in day light). This means that the two garments will not longer match in day light.

In short: two colors match under one light source, but not under another.

How do you know if there is metamerism? and what to do if there is
- You can carry out a visual assessment and compare the magnitude of the color difference of the sample to the standard under each light source
- If the color difference is greater under one source than the other, then the sample is metameric
- For technical reasons, metamerism may be unavoidable in some cases
- If a mill is unable to match a color due to metamerism, the lab manager should include a note with the labdip submit explaining the technical limitations encountered
- To be proactive, ask an expert to carry out a feasibility study and if needed to create a digital optimized standard curve

2. Color Constance vs. Inconstant Color
If a color of only ONE sample appears equal within two different lights, the color is constant. If the one sample is different in the two lights, the color is inconstant.







3. Speak the same color language throughout your supply chain
It is necessary to communicate clearly and consistently sharing a mutual language throughout the supply chain when it comes to describing color differences. The textile industry uses below guidelines and terminology for describing color differences. Your acceptable difference is defined by your color tolerance value.

For chromatic colors (i.e. colors that have one particular wavelength or hue that dominant, such as yellow, orange, red, purple, blue, turquoise, and green): Color differences between a color standard and a sample of chromatic colors are described using comments about their cylindrical color coordinates.

Following three color difference values are commonly used for chromatic colors:
hue (DH*)
lightness (DL*)
chromaticity (DC*)

Hue: Hue is the “color” of a color or its identity such as red, orange, green, etc. Your comments are based on whether the DH value of the sample is positive or negative compared to the standard.

Lightness:
A colors degree of lightness is the luminous intensity of a color. Colors can be classified as light or dark when comparing their value.
+DL* means that the sample is lighter than the standard
–DL* means that the sample is darker than the standard

Chroma:
Chroma describes the brightness or dullness of a color. In other words, how close the color is to either gray or the pure hue. Chroma is also known as saturation.
+DC* means that the sample is brighter than the standard
–DC* means that the sample is duller than the standard

For achromatic colors (i.e. colors where all wavelengths are present in equal amounts within those such as brown, olive, grey, white, black): Color differences between a standard and a sample of achromatic colors are described using comments about their cartesian color coordinates.

Following three color difference values are commonly used:
lightness (DL*)
red/green axis (Da*)
yellow/blue axis (Db*)

Lightness:
+DL* means that the sample is lighter than the standard
–DL* means that the sample is darker than the standard

Red/Green:
+Da* means that the sample is redder than the standard
–Da* means that the sample is greener than the standard

Yellow/Blue:
+Db* means that the sample is yellower than the standard
–Db* means that the sample is bluer than the standard






Wanna learn more? Click here to find out what most people don’t know about Color Standards.



                    


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